Intro to cytology

Question 1

plasma membrane

Answer 1

site where materials exchanged into and out of cell; maintains cytoplasm ion concentration and has recognition and regulatory functions

• 7.5 to 10 nm in thickness (need EM)
• trilaminar appearance

Question 2

endocytosis

Answer 2

bulk uptake of material into cell. Three kinds

1. Phagocytosis
2. Pinocytosis
3. Receptor-mediated endocytosis

Question 3

exocytosis

Answer 3

release of material across the plasma membrane into the extracellular space; vesicle fuses with PM and releases its products

Question 4

lysosomes

Answer 4

sites of intracellular digestion and turnover of cell components
-0.05 micrometers to 0.5 micrometers

Question 5

ribosomes

Answer 5

function: protein synthesis

- 20 and 30 nm

Question 6

endoplasmic reticulum

Answer 6

1. RER

2. SER

Question 7

RER

Answer 7

ribosomes of cytosolic side of membrane; produces proteins for secretion –> STAIN BASOPHILIC

Question 8

SER

Answer 8

important in production of phospholipids, detox, and steroid synthesis

Question 9

golgi apparatus

Answer 9

completes post-translational modifications, packages and sorts proteins synthesized in the RER; has cis and trans faces

Question 10

mitochondria

Answer 10

has enzyme arrays specialized for aerobic respiration and production of ATP

• 0.5 to 1 micrometer in diameter
• 5-10 micrometer in length

Question 11

secretory vesicles or granules

Answer 11

formed at the golgi apparatus; store product until released via exocytosis

Question 12

proteasomes

Answer 12

degrade denatured and nonfunctional polypeptides

Question 13

peroxisomes

Answer 13

oxidize various potentially toxic molecules well as prescription drugs
- 0.5 micrometers in diameter

Question 14

microtubules

Answer 14

involved in formation and maintenance of cell shape; cell transport of organelles and vesicles; creates repeated beating motion

• outer diameter = 24 nm
• wall = 5nm
• length is variable

Question 15

microfilaments (actin filaments)

Answer 15

allow for contractile activity in the cells, including cell shape changes for endocytosis, exocytosis, and cell locomotion , moving cytoplasmic components and cleavage during mitosis
-5-9nm

Question 16

intermediate filaments

Answer 16

provide mechanical strength and stability

-10-12 nm in diameter

Question 17

inclusions

Answer 17

cytoplasmic structures or deposits composed mainly of accumulated metabolites or other substances (not considered organelles)
ex: lipid droplets, glycogen granules, pigment deposits

Question 18

nucleus

Answer 18

1. nuclear envelope
2. Chromatin
3. nucleolus

Question 19

heterochromatin

Answer 19

course chromatin in EM and basophilic clumps in light microscopy: not active chromatin

Question 20

euchromatin

Answer 20

less coiled, fine granules in EM and lightly basophilic areas in light microscopy (being used to form proteins- active cell)

Question 21

apoptosis

Answer 21

the process of cell suicide or programmed cell death; leads to the production of small membrane-enclosed apoptotic bodies which undergo phagocytosis by neighboring cells